Assessing synergies and conflicts arriving from spatial-temporal proximity between marine human-based uses

The pressures on marine ecosystems and on marine space are increasing due to expanding marine human-based activities. Traditional uses e.g. fishing, shipping, oil and gas development, tourism, and recreation compete for marine space with each other and with relatively new marine uses such as sustainable energy, marine biotechnology, and aquaculture. The Blue Growth Strategy of the European Union highlights blue potentials for economic sectors to increase the use of marine resources and marine space. Within an ecosystem-based approach to maritime spatial planning and to blue growth, it is important to limit cumulated pressures on the environment. While it is crucial to examine synergies and conflicts between human-based uses and the environment, it is also important to examine conflicts and synergies in the interactions between different human-based uses, especially if they experience a close proximity in space and time.
A cross-sectoral theoretical framework to assess spatial-temporal synergies and conflicts between marine uses in maritime spatial planning is needed. By knowing potential and actual conflicts and synergies between marine uses and their dependencies on ecosystem services, planners can implement means to avoid or at least minimise conflicts between uses as well as maximising interaction-based synergies. At the same time, a focus on synergies can increase the awareness of options to co-locate marine uses in the future to decrease pressures on space elsewhere and optimise the use of space.
A pairwise matrix-based approach to assess conflicts and synergies that arrive from marine human-based uses being in spatial-temporal close proximity to each other will be presented. Firstly, the approach can be used at a larger regional basin-wide scale to produce raster-based maps that show potential conflicts and potential synergies between human-based uses in a marine area based on theoretical knowledge about synergies and conflicts between marine uses. Secondly, it can be used as a survey-based protocol for gathering expert-based knowledge on existing or scenario-based conflicts and synergies at a more local spatial scale, particularly relevant to apply in coastal zones that contain many different marine uses. Thirdly, the approach provides a catalogue for which marine uses that can coexist side by side or be combined into multi-use constellations. Besides the need for local and sector-specific expert-knowledge, the approach needs access to spatial GIS-data of marine human-based uses where the map-based application of the tool depends on the spatial resolution of the data.